rhg: Fall back to Python if ui.relative-paths is configured This feature is not supported yet, and affects the output of some tests. Differential Revision: https://phab.mercurial-scm.org/D10137

tests: clarify some missing output in test-merge-subrepos This makes the test behavior clearer, especially, why the output are inconsistent. Differential Revision: https://phab.mercurial-scm.org/D10136

tests: Adapt expected output for minor differences with rhg Differential Revision: https://phab.mercurial-scm.org/D10135

rhg: Add support for --cwd This affect the meaning of relative paths in `--repository`, which are resolved "early" by rhg in order to load config which is needed before fallback to Python is considered. An incorrect path could cause errors when loading a non-existent repo, leading to failing tests even when fallback is enabled. Differential Revision: https://phab.mercurial-scm.org/D10134

rhg: Align with Python on some more error messages Differences can cause some tests to fail Differential Revision: https://phab.mercurial-scm.org/D10133

rhg: Add an allow-list of ignored extensions Because rhg doesn’t know how a Python extension would affect behavior it implements in Rust, when an unsupported extension is enabled it conservatively falls back to Python-based hg. However many users will have unsupported extensions enabled in practice. Maybe they don’t actually affect rhg behavior, but we don’t know. This adds a `rhg.ignored-extensions` configuration that lets users list extensions that rhg can safely ignore and proceed even if they’re not supported in Rust. Differential Revision: https://phab.mercurial-scm.org/D10188

rhg: Fall back to Python if unsupported extensions are enabled Extensions might affect behavior in ways we can’t anticipate, so just ignoring them is not correct. Later we’ll add opt-in configuration to ignore specific extensions. Differential Revision: https://phab.mercurial-scm.org/D10112

rhg: Sort config files when adding a directory For example in `/etc/mercurial/hgrc.d/` or with `HGRCPATH=some-directory`. Previously files where parsed in the order returned by the filesystem, which is undefined. But order is significant when multiple files define the same configuration key: the "last" one wins. Differential Revision: https://phab.mercurial-scm.org/D10111

rhg: Align config file parse error formatting with Python Differences can cause tests to fail Differential Revision: https://phab.mercurial-scm.org/D10110

rhg: Fall back to Python for bundle repositories rhg does not support bundles at all, yet. Differential Revision: https://phab.mercurial-scm.org/D10102

rhg: Fall back to Python on --repository with an URL A low-hanging fruit to improve on this would be to properly parse and handle `file:` URLs. But other Python-based hg supports some other URL schemes for features that rhg does not support yet. Differential Revision: https://phab.mercurial-scm.org/D10101

rhg: Print non-absolutized path in "repository {} not found" errors … like Python does. Differences in ouput can cause tests to fail. Differential Revision: https://phab.mercurial-scm.org/D10100